Department of Mechanical Engineering, Maulana Azad National Institute of Technology, Bhopal 462003, Madhya Pradesh, India.
Department of Mechanical Engineering, Maulana Azad National Institute of Technology, Bhopal 462003, Madhya Pradesh, India.
Med Eng Phys. 2020 Jul;81:86-96. doi: 10.1016/j.medengphy.2020.05.010. Epub 2020 May 17.
Biodegradable materials have been generating increasing bit of interest in biomedical applications and associated research. The evolution of implants made up of such materials (Mg-alloys, etc.) has the potential to be a game changer in fracture surgeries. These implants are essentially made up of a plate and a number of screws. In orthopaedic applications, they offer the biggest advantage of complete degradation after successfully supporting the fractured bone for the desired period. They may provide some nutrients that accelerate the healing process while simultaneously ensuring adequate mechanical stability. This article essentially focuses on design of a biodegradable implant plate for femoral shaft fracture, taking into consideration the dimensional accuracy of the plate, uniform biodegradation rate and adequate mechanical stability of the plate across the entire process span. The design of a biodegradable implant plate and associated specified screws that support the plate, fitted over two segments for fixation of femoral shaft fracture, has been made on the basis of femur's standard dimensions, optimized plate dimensions and uniform biodegradation rate. A confirmation regarding the safe design of the implant plate is obtained through computational structural analysis. The implant plate design turns out to be safe at specific optimized dimensions for a human being weighing 80 Kg, at corresponding loading and boundary conditions. For average monthly degradation of the plate across a period of six months, the factor of safety comes out to be more than unity. The implant plate eventually goes through complete degradation 3-6 months after the completion of the healing process and this is where the plate thickness plays a significant role.
可生物降解材料在生物医学应用和相关研究中引起了越来越多的关注。由这类材料（镁合金等）制成的植入物的发展有可能彻底改变骨折手术。这些植入物主要由一个板和一些螺丝组成。在骨科应用中，它们提供了最大的优势，即在成功支撑骨折骨骼所需的时间后完全降解。它们可以提供一些加速愈合过程的营养物质，同时确保足够的机械稳定性。本文主要关注设计一种用于股骨干骨折的可生物降解植入板，考虑到板的尺寸精度、均匀的生物降解率和整个过程中板的足够机械稳定性。在股骨标准尺寸、优化的板尺寸和均匀的生物降解率的基础上，设计了一种可生物降解的植入板和与之配套的固定螺丝，以支撑板。通过计算结构分析对植入板的安全设计进行了验证。在特定的优化尺寸下，对于体重为 80 公斤的人来说，植入板设计是安全的，在相应的加载和边界条件下也是安全的。在六个月的时间内，板的平均每月降解量，安全系数大于 1。植入板最终会在愈合过程完成后 3-6 个月内完全降解，而这正是板厚度起着重要作用的地方。
